Genuineness detecting system and method for using genuineness detecting film

ABSTRACT

An authenticity identifying film ( 10 ) has a reflective film ( 11 ) having a circularly polarized light selectivity to reflect at least only either of right-handed circularly polarized light and left-handed circularly polarized light of incident light to produce reflected light. The reflective film ( 11 ) is provided with a hologram forming part ( 11   a ). The hologram forming part ( 11   a ) reflects circularly polarized light of the same circular polarization as that of the reflected light in a direction different from that of the reflected light to form a holographic image. The reflected light reflected by the reflective film ( 11 ) and the holographic image formed by the hologram forming part ( 11   a ) are detected by detectors disposed at different positions, respectively.

TECHNICAL FIELD

The present invention relates to an authenticity identifying film andauthenticity identifying system for preventing the forgery of articlesincluding cards, gift certificates, currency notes, tickets, bank notes,securities, betting tickets and the like, and a method of using theauthenticity identification film.

BACKGROUND ART

A conventional method of preventing the forgery of credit cards, deeds,currency notes and the like attaches an authenticity identifying mediumwhich is difficult to forge to an article to be protected from forgery,and identifies the authenticity identifying medium visually ormechanically. A hologram or a liquid crystal film is used as theauthenticity identifying medium.

Holograms include those carrying a holographic image of characters andpatterns for visual identification, those carrying a holographic imageof numerical codes and special patterns for mechanical recognition, andthose carrying both the foregoing holographic images. The hologram hasbeen prevalently used because the hologram cannot be copied by anordinary color copying machine or the like and is effective in forgeryprevention, the hologram is attractive because of its highly aestheticdesign, the hologram is difficult to produce and hence the hologram hasbeen prevalently used.

Previously proposed methods employing liquid crystal films includes amethod proposed in JP-A No. Sho 63-51193 using a cholesteric liquidcrystal which looks in different colors when seen from differentdirections, and a method proposed in JP-A No. Hei 8-43804 using anoptically anisotropic nematic liquid crystal. The method using acholesteric liquid crystal is able to record two characteristics of thecholesteric liquid crystal, namely, selective reflectivity and circularpolarization selectivity, as information for authenticity identificationon a single medium, mass-production of a cholesteric liquid crystal offixed properties is difficult and hence this method is excellent inforgery preventing effect.

However, recently prevalent hologram producing techniques have madepossible the production of counterfeits of conventional holograms, whichreduced the forgery preventing effect of the conventional holograms.

Although the forging of liquid crystal films is difficult, the massproduction of authentic liquid crystal films also is difficult, andhence liquid crystal films have not been prevalently used asauthenticity identification mediums.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide an authenticityidentifying film having a highly esthetic design, difficult to forge andfacilitating either visual or mechanical authenticity identification, anauthenticity identifying system and a method of using the authenticityidentifying film.

An authenticity identifying film according to the present inventionincludes a reflective film having a circularly polarized lightselectivity to reflect only either of right-handed circularly polarizedlight or left-handed circularly polarized light of at least incidentlight to produce reflected light, wherein the reflective film isprovided with a hologram forming part that reflects circularly polarizedlight of the same circular polarization as that of the reflected lightin a direction different from that of the reflected light to form aholographic image.

An authenticity identifying film according to the present inventionincludes a reflective film having a circularly polarized lightselectivity to reflect only either of right-handed circularly polarizedlight or left-handed circularly polarized light of at least incidentlight to produce reflected light, and a hologram forming layer laminatedto the reflective film having a hologram forming part that reflectscircularly polarized light of circular polarization opposite that of thereflected light in a direction different from that of the reflectedlight to form a holographic image.

The authenticity identifying film according to the present invention ischaracterized in that the reflective film is a liquid crystal film.

The authenticity identifying film according to the present invention ischaracterized in that the reflective film has a fixed cholesteric phase.

The authenticity identifying film according to the present invention ischaracterized in that the hologram forming part includes an embossedhologram.

The authenticity identifying film according to the present invention mayfurther include an adhesive layer to be attached to an article.

The authenticity identifying film according to the present invention ischaracterized in that the reflective film is delaminated when theauthenticity identifying film is separated from an article.

The authenticity identifying film according to the present invention mayfurther include a protective film covering a surface of the reflectivefilm opposite a surface of the same facing an article.

The authenticity identifying film according to the present invention mayfurther include a base film attached by an additional adhesive layer toa surface of the reflective film opposite a surface of the same facingan article.

The authenticity identifying film according to the present invention mayfurther include a light absorbing layer interposed between thereflective film and the adhesive layer.

An article with an authenticity identifying film according to thepresent invention comprises: an authenticity identifying film includinga reflective film having a circularly polarized light selectivity toreflect only either of right-handed circularly polarized light orleft-handed circularly polarized light of at least incident light toproduce reflected light, the reflective film being provided with ahologram forming part that reflects circularly polarized light of thesame circular polarization as that of the reflected light in a directiondifferent from that of the reflected light to form a holographic image,or an authenticity identifying film including a reflective film having acircularly polarized light selectivity to reflect only either ofright-handed circularly polarized light or left-handed circularlypolarized light of at least incident light to produce reflected light,and a hologram forming layer laminated to the reflective film, having ahologram forming part that reflects circularly polarized light ofcircular polarization opposite that of the reflected light in adirection different from that of the reflected light to form aholographic image; an article to which the authenticity identifying filmis bonded; and a photograph interposed between the article and theauthenticity identifying film.

An authenticity identifying system according to the present inventioncomprises: an authenticity identifying film including a reflective filmhaving a circularly polarized light selectivity to reflect only eitherof right-handed circularly polarized light or left-handed circularlypolarized light of at least incident light to produce reflected light,the reflective film being provided with a hologram forming part thatreflects circularly polarized light of the same circular polarization asthat of the reflected light in a direction different from that of thereflected light to form a holographic image, or an authenticityidentifying film including a reflective film having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofat least incident light to produce reflected light, and a hologramforming layer laminated to the reflective film, having a hologramforming part that reflects circularly polarized light of circularpolarization opposite that of the reflected light in a directiondifferent from that of the reflected light to form a holographic image;a light source unit that irradiates the authenticity identifying filmwith light; and a detecting unit for detecting reflected light from theauthenticity identifying film and the holographic image.

In the authenticity identifying system according to the presentinvention, the detecting unit is capable of detecting only light in apredetermined waveband.

In the authenticity identifying system according to the presentinvention, the detecting unit is capable of measuring the intensity oftransmitted light.

In the authenticity identifying system according to the presentinvention, at least either the light source unit or the detecting unitis provided with a polarizing plate, a phase plate or a band-passfilter.

According to the present invention, a method of using an authenticityidentifying film including a reflective film having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofat least incident light to produce reflected light, the reflective filmbeing provided with a hologram forming part that reflects circularlypolarized light of the same circular polarization as that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, or an authenticity identifying filmincluding a reflective film having a circularly polarized lightselectivity to reflect only either of right-handed circularly polarizedlight or left-handed circularly polarized light of at least incidentlight to produce reflected light, and a hologram forming layer laminatedto the reflective film, having a hologram forming part that reflectscircularly polarized light of circular polarization opposite that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, the method comprising the steps of:irradiating the authenticity identifying film with right-handedcircularly polarized light or left-handed circularly polarized light;and deciding that the authenticity identifying film is authentic wheneither of right-handed circularly polarized light and left-handedcircularly polarized light can be detected and the other circularlypolarized light cannot be detected.

According to the present invention, a method of using an authenticityidentifying film including a reflective film having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light and left-handed circularly polarized light ofat least incident light to produce reflected light, the reflective filmbeing provided with a hologram forming part that reflects circularlypolarized light of the same circular polarization as that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, or an authenticity identifying filmincluding a reflective film having a circularly polarized lightselectivity to reflect only either of right-handed circularly polarizedlight and left-handed circularly polarized light of at least incidentlight to produce reflected light, and a hologram forming layer laminatedto the reflective film, having a hologram forming part that reflectscircularly polarized light of circular polarization opposite that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, the method comprising the steps of:irradiating the authenticity identifying film with light includingright-handed circularly polarized light and left-handed circularlypolarized light; and deciding that the authenticity identifying film isauthentic when the holographic image from the authenticity identifyingfilm can be read from the authenticity identifying film in a directiondifferent from that of the reflected light.

According to the present invention, a method of using an authenticityidentifying film including a reflective film having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light and left-handed circularly polarized light ofat least incident light to produce reflected light, the reflective filmbeing provided with a hologram forming part that reflects circularlypolarized light of the same circular polarization as that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, or an authenticity identifying filmincluding a reflective film laminated to the reflective film, having acircularly polarized light selectivity to reflect only either ofright-handed circularly polarized light and left-handed circularlypolarized light of at least incident light to produce reflected light,and a hologram forming layer having a hologram forming part thatreflects circularly polarized light of circular polarization oppositethat of the reflected light in a direction different from that of thereflected light to form a holographic image and laminated to thereflective film, the method comprising the steps of: irradiating theauthenticity identifying film with light including right-handedcircularly polarized light and left-handed circularly polarized light;and deciding that the authenticity identifying film is authentic whenthe film has a part that cannot be visually recognized when theauthenticity identifying film is observed visually through an examiningtool that transmits only either of right-handed circularly polarizedlight and left-handed circularly polarized light.

According to the present invention, a method of using an authenticityidentifying film including a reflective film having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light and left-handed circularly polarized light ofat least incident light to produce reflected light, the reflective filmbeing provided with a hologram forming part that reflects circularlypolarized light of the same circular polarization as that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, or an authenticity identifying filmincluding a reflective film having a circularly polarized lightselectivity to reflect only either of right-handed circularly polarizedlight and left-handed circularly polarized light of at least incidentlight to produce reflected light, and a hologram forming layer laminatedto the reflecting film, having a hologram forming part that reflectscircularly polarized light of circular polarization opposite that of thereflected light in a direction different from that of the reflectedlight to form a holographic image, the method comprising the steps of:irradiating the authenticity identifying film with light includingright-handed circularly polarized light and left-handed circularlypolarized light; and measuring the light intensity difference betweenthe intensities of right-handed circularly polarized light and that ofthe intensity of left-handed circularly polarized light transmitted byan examining tool that transmits only either of right-handed circularlypolarized light and left-handed circularly polarized light and decidingwhether or not the authenticity identifying film is authentic on thebasis of the light intensity difference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a typical sectional view of an authenticity identifying filmin an embodiment 1-1 according to the present invention;

FIG. 2 is a typical view of a cholesteric liquid crystal contained in anauthenticity identifying film according to the present invention;

FIG. 3 is a graph showing, by way of example, an intensity-wavelengthcharacteristic of reflected light reflected by an authenticityidentifying film according to the present invention;

FIGS. 4(A) and 4(B) are views of assistance in explaining anauthenticity identifying system employing an authenticity identifyingfilm according to the present invention;

FIG. 5 is a view of assistance in explaining a method of using anauthenticity identifying film in an embodiment 1-2 according to thepresent invention;

FIG. 6 is a typical sectional view of assistance in explaining a methodof using an authenticity identifying film in an embodiment 1-3 accordingto the present invention;

FIG. 7 is a typical sectional view of an authenticity identifying filmin an embodiment 2-1 according to the present invention;

FIG. 8 is a plan view of an authenticity identifying film in anembodiment 2-2 according to the present invention;

FIG. 9 is a plan view of the authenticity identifying film in theembodiment 2-2;

FIG. 10 is a plan view of the authenticity identifying film in theembodiment 2-2;

FIG. 11 is a view of assistance in explaining a method of applying anauthenticity identifying film in an embodiment 2-3 according to thepresent invention to an article; and

FIG. 12 is a plan view of an article in an embodiment 2-4 according tothe present invention to be subjected to authenticity identification anda circularly polarizing plate.

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

Preferred embodiments of the present invention will be describedhereinafter.

Embodiment 1-1

FIG. 1 is a sectional view of an authenticity identifying film in anembodiment 1-1 according to the present invention.

An authenticity identifying film 10 has a reflective film 11,aprotective layer 12, a light absorbing layer 13 and a base film 14.

The reflective film 11 reflects only either of right-handed circularlypolarized light and left-handed circularly polarized light of incidentlight to produce reflected light. A hologram forming part 11 a is formedin one of the surfaces of the reflective film 11. The hologram formingpart 11 a reflects light of the same circular polarization as that ofthe reflected light reflected by the reflective film 11 in a directiondifferent from that of the reflected light to form a holographic image.The reflective film 11 reflects only either of right-handed circularlypolarized light and left-handed circularly polarized light on itssurface contiguous with the protective layer 12 or in the reflectivefilm 11 to produce reflected light. Light of the same circularpolarization as that of the reflected light reaches the hologram formingpart 11 a and is reflected on the hologram forming part 11 a in adirection different from that of the reflected light by the hologramforming part 11 a to form a holographic image.

The reflective film 11 has a cholesteric liquid crystal phase. The meanscrew axis orientation of the cholesteric liquid crystal phase isparallel to the thickness of the film. Cholesteric liquid crystal willbe described later.

The reflective film 11 may be any one of mediums having opticalselective reflectivity and circularly polarized light selectivity, suchas polymer films formed through the fixation of cholesteric liquidcrystal orientation and films formed by dispersing a cholesteric liquidcrystal in mediums. A polymer film formed through the fixation of liquidcrystal orientation is particularly suitable.

A possible polymer film is formed by orienting a low molecular-weightliquid crystal in a cholesteric orientation and fixing the cholestericorientation by cross-linking the low molecular-weight liquid crystal bya photoreaction or a thermal reaction. Another possible polymer film isformed by cholesteric-orienting a side chain type or main chain typethermotropic high-molecular liquid crystal in a liquid crystal state,cooling the oriented thermotropic chain-molecular liquid crystal at atemperature not higher than the transition point to fix the orientedstate of the liquid crystal. A third possible polymer film is formed bycholesteric-orienting a side chain type or a main chain type lyotroichigh-molecular liquid crystal in a solution and fixing the orientatedstate by gradually removing the solvent.

High-molecular liquid crystals suitable for forming such films are sidechain type polymers having liquid crystal forming groups on side chains,such as polyacrylates, polymethacrylates, polysiloxanes andpolymalonates, and main chain type polymers having liquid crystalforming groups on main chains, such as polyesters, polyester amides,polycarbonates, polyamides and polyimides.

The hologram forming part 11 a is formed by embossing one surface of thereflective film 11 with minute irregularities with a master hologramembossing die to transfer a pattern formed on the master hologramembossing die to the surface. When embossing the surface of thereflective film 11, heat and pressure is applied to the reflective film11 by a press, a rolling mill, a calender, a laminator or a stamper.Another method applies a cholesteric liquid crystal to a master hologramdie in a cholesteric liquid crystal layer and orients the cholestericliquid crystal on the master hologram die. The hologram forming part 11a reflects light in a direction different from that of reflected lightreflected by the reflective film 11 to form a holographic image.

The protective layer 12 protects the reflective film 11. Suitablematerials for forming the protective layer 12 are acrylic resins,urethane resins, epoxy resins, silicone resins, EVA resins, polyamideresins, polyester resins, polystyrene resins, cellulose resins andmixtures of some of those resins. Materials of the protective layer 12are not limited to the foregoing resins. It is desirable to determine amaterial for forming the protective layer 12 selectively taking intoconsideration required properties of the surface of the authenticityidentifying film 10 including smoothness, hardness and abrasionresistance.

The light absorbing layer 13 absorbs light penetrating through thereflective film 11. The light absorbing layer 13 may be formed of, forexample, a black ink. Since the light absorbing layer 13 absorbs thelight penetrating through the reflective film 11, undesirable reflectionof transmitted light can be prevented, which facilitates the visualrecognition of the holographic image.

From the view point of aesthetic design, the light absorbing layer 13may be a color layer formed of a color ink or the like and capable ofabsorbing light in a specific waveband of the light penetrated thereflective film 11.

The base film 14 is provides the authenticity identifying film 10 with aself-supporting ability. The material of the base film 14 may bedetermined according to a purpose of the authenticity identifying film10 and there is no particular restriction on the material of the basefilm 14. Particularly preferable materials for forming the base film 14are polycarbonates, polyvinyl alcohols, polysulfones, polyethylenes,polypropylenes, polystyrenes, polyarylates, polyethylene terephthalates,triacetyl cellulose, diacetyl cellulose, and poly(ethylene-co-vinylalcohol). The base film 14 may be a film of a mixture of one of theforegoing material and a high-molecular liquid crystal.

FIG. 2 is a typical view of a cholesteric liquid crystal contained in anauthenticity identifying film according to the present invention, andFIG. 3 is a graph showing, by way of example, an intensity-wavelengthcharacteristic of reflected light reflected by an authenticityidentifying film according to the present invention.

Explanation of Cholesteric Liquid Crystal

A cholesteric liquid crystal has elongated molecules parallel to eachother within the plane of a layer, but the direction of orientation istwisted slightly from layer to layer in the direction of thickness ofthe film to form a helix through the layers as shown in FIG. 2. When thepitch P (thickness necessary for liquid crystal molecules turn through360°) and the wavelength λ of the incident light is substantially equalto each other, the cholesteric liquid crystal exercises two opticalproperties, namely, a selective reflectivity and circular polarizationselectivity (Reference literature: Ekishyou to Disupurei Oyou no Kiso,Corona).

Selective refractivity is a property to reflect light in a specificwaveband more strongly than light of a wavelength in other waveband(FIG. 3). Since the selective reflectivity is exhibited for a specificwaveband, the reflected light has a chromatic color of a high colorpurity when a cholesteric liquid crystal having a proper pitch P isselected. The center wavelength of the waveband λs and the bandwidth Δλare expressed by Expressions (1) and (2).

λs=nm·P  (1)

Δλ=Δn·P/nm  (2)

where nm (={square root over ((no²+ne²)/2))}, ne is extraordinary rayreflective index in a plane in an optical medium, no is ordinaryreflective index and Δn=ne−no.

The center wavelength λs and the bandwidth Δλ expressed by Expressions(1) and (2) are defined for vertical incidence of light on thecholesteric liquid crystal layer (0°-incidence, on-axis incidence). Ifthe incident light falls obliquely on the cholesteric liquid crystallayer (off-axis incidence), the pitch P decreases apparently and,consequently, the center wavelength λs shifts toward theshorter-wavelength side and the bandwidth Δλ decreases. This phenomenonis called blue shift because the center wavelength λs shifts toward theshorter-wavelength side. The shift of the center wavelength λs isdependent on the incident angle and is readily distinguishable by visualobservation. For example, reflected light from the cholesteric liquidcrystal is red when the cholesteric liquid crystal is observed in adirection perpendicular to the surface (direction of 0°-incidence). Asthe observation angle to a perpendicular to the surface increases, theobserved color of the reflected light changes from red, through orange,yellow, green, bluish green to blue.

The circular polarization selectivity is a property that transmitscircularly polarized light having a displacement vector that rotates ina specific direction and reflects circularly polarized light having adisplacement vector that rotates in a direction opposite the specificdirection. Circularly polarized light included in the incident light andpolarized in the same direction as that of twisting of elongatedmolecules of the cholesteric liquid crystal is reflected and therotating direction of the reflected light becomes the same. Circularlypolarized light included in the incident light and polarized in adirection opposite the direction of twisting of elongated molecules ofthe cholesteric liquid crystal is transmitted. These are the uniqueproperties of the cholesteric liquid crystal. A right-handed cholestericliquid crystal reflects a right-handed circularly polarized lightcomponent and transmits a left-handed polarized light component. Thereflected light is right-handed polarized light.

Explanation of Hologram

A hologram is a desired pattern, an image or characters formed bychanging the grading constant and the diffraction direction of adiffraction grating formed on an article in a small region correspondingto a pixel size. Holograms are classified by construction into volumeholograms and plane holograms, or by light modulating system intoamplitude holograms and phase holograms. Modulation plane holograms(embossed holograms) which can be mass-produced by a microreplicaprocess are used widely in industries. To form a sharp holographic imagein the visible region, the grating constant of the diffraction gratingmust be very precisely controlled so as to fall in the range of about 10μm to about 100 nm. Therefore, the fabrication of a master die and themanufacture of replicas require proficient processing techniques.

As shown in FIG. 3, the hologram reflects light of a wavelength in aspecific waveband strongly, authenticity identification can be achievedthrough the observation of the wavelength of the reflected light.

Using Method

FIGS. 4(A) and 4(B) are views of assistance in explaining anauthenticity identifying system employing the authenticity identifyingfilm according to the present invention. FIG. 4(A) is a typicalsectional view of the authenticity identifying film and FIG. 4(B) is aperspective view of the authenticity identifying film.

The authenticity identifying film 10 is attached to an article 20, i.e.,a subject of authenticity identification, with an adhesive layer 45(FIG. 7) by a thermal transfer method, a sealing method, a thread methodor a thermal transfer ribbon method. The article 20 is, for example, aplastic card, such as a credit card, a banking card or an ID card, asecurity, such as a gift certificate, a currency note, a gift check or astock certificate, a PET card, such as a prepaid card or a commuterticket, tickets, a bank note, a passport or a betting ticket, which,however is not restrictive.

When the twisting direction of the cholesteric liquid crystal phase ofthe reflective film 11 is a right-hand direction (counterclockwisedirection) and a light source 21 emits natural light, a detector 22 adisposed so as to receive regularly reflected light reflected in adirection indicated by the arrow followed by a solid line receivesright-handed circularly polarized light of reflected light reflected bythe reflective film 11. In FIG. 4(A), the right-handed circularlypolarized light is shown, for convenience, as if the same is reflectedonly by the surface of the reflective film 11 contiguous with theprotective layer 12 to produce reflected light. Actually, the reflectedlight includes right-handed polarized light reflected by the interior ofthe reflective film 11.

A detector 22 b disposed so as to receive reflected light reflected inthe direction of the arrow followed by a broken line is able to detect aholographic image formed by light component reflected and diffracted bythe hologram forming part 11 a formed in the other surface of thereflective film 11. The light reflected by the hologram forming part 11a right-handed circularly polarized light component, which is the sameas the reflected light. If a circularly polarizing plate or acombination of a linearly polarizing plate and a phase film isincorporated into the detector 22 a to distinguish the rotatingdirection of circularly polarized light, light is transmitted by aright-handed circularly polarizing plate and the same can be detected,and light is absorbed by a left-handed circularly polarizing plate andthe same cannot be detected. Thus, the reflected light can be readilyrecognized if the same is right-handed polarized light. Since anordinary reflector does not have circularly polarized light selectivity,the reflected light can be detected by using either of a right-handedcircularly polarizing plate and a left-handed circularly polarizingplate. According to the present invention, the authenticity of theauthenticity identifying film 10 can be easily distinguished by anauthenticity identifying system shown in FIGS. 4(A) and 4(B).

A band-pass filter for distinguishing the color of circularly polarizedlight may be incorporated into the light source unit 21 or a band-passfilter or a spectroscopic system for distinguishing the color ofcircularly polarized light may be incorporated into the detector 22 a todistinguish the wavelength selectivity of the reflective film 11. Whenthe wavelength selectivity of the reflective film 11 can be thusdistinguished, it is possible to distinguish easily the authenticity ofthe authenticity identifying film 10 by examining the reflected light tosee whether or not the reflected light has a wavelength in a desiredwaveband. Electrooptic detection also is possible.

The hologram forming part 11 a of the reflective film 11 may be providedwith a ciphered authenticity identifying code represented by thedirection of diffraction or the wavelength of diffracted light. Theauthenticity of the authenticity identifying film 10 can be easilydistinguished by receiving a holographic image formed by the hologramforming part 11 a by the detector 22 b and distinguishing theauthenticity of the holographic image by an authenticity distinguishingdecoder 23 combined with the detector 22 b.

Authenticity can be more exactly distinguished by emitting circularlypolarized light by the light source unit 21. When right-handedcircularly polarized light is emitted by the light source unit 21,cholesteric reflection can be observed by the detector 22 a disposed soas to receive regularly reflected light and a holographic image can beobserved by the detector 22 b disposed at a position displaced from thepassage of the regularly reflected light. When left-handed circularlypolarized light is emitted by the light source unit 21, no reflectedlight is produced, any holographic image is not formed and only thecolor of the light absorbing layer 13 can be observed.

Thus, the authenticity identifying system may be provided, in additionto the light source unit 21 and the detectors 22 a and 22 b, with thecircularly polarizing plate, the linearly polarizing plate, the phaseplate, the band-pass filter, the spectroscopic system and theauthenticity identifying decoder 23 to distinguish the rotatingdirection of the circularly polarized light included in the reflectedlight and the reflection waveband and to decode the authenticityidentifying code represented by the holographic image. When theauthenticity identifying system is provided with those additionalcomponents, the authenticity of the authenticity identifying film 10 canbe more accurately distinguished. Electrooptic detection also ispossible.

Since the reflective film 11 employed in this embodiment has thecholesteric liquid crystal phase, the reflected light from thereflective film 11 is the circularly polarized light. Therefore, theauthenticity of the authenticity identifying film 10 can be easilydistinguished by detecting the reflected light by the detector 22 aprovided with the circularly polarizing plate. Since the reflected lighthas a wavelength in a specific waveband, the authenticity of theauthenticity identifying film 10 can be easily distinguished throughvisual observation, and the authenticity can be more accuratelydistinguished by mechanical reading.

Since the reflective film 11 is provided with the hologram forming part11 a in one surface thereof, the authenticity of the authenticityidentifying film 10 can be easily distinguished by detecting aholographic image formed by diffracted light reflected by the hologramforming part 11 a at a reflection angle other than the regularreflection angle by the detector 22 b.

Embodiment 1-2

FIG. 5 is a view of assistance in explaining a method of using anauthenticity identifying film in an embodiment 1-2 according to thepresent invention.

In the following description of the embodiment 1-2, parts functionallysimilar to those previously mentioned in the description of theembodiment 1-1 are designated by the same reference characters and thedescription thereof will be omitted to avoid duplication.

FIG. 5 shows an article 20 to which an authenticity identifying film 10provided with a hologram forming part 11 a that forms a hologram ofcharacters, pictures, patterns or the like.

When the article 20 is irradiated with natural light (nonpolarizedlight), reflected light from a part of the article to which theauthenticity identifying film 10 is attached is circularly polarizedlight. When the twisting direction of the cholesteric liquid crystalphase of the reflective film 11 is a right-hand direction(counterclockwise direction), the reflected light reflected by thereflective film 11 and a holographic image are right-handed circularlypolarized light. When the reflected light and the holographic image areobserved through a circularly polarizing plate 30 having a left-handcircularly polarizing part 30 a that transmits left-handed circularlypolarized light, and a right-hand circularly polarizing part 30 bdisposed contiguously with the left-hand circularly polarizing part 30a, transmitting right-handed circularly polarized light, the selectivelyreflected light reflected by the authenticity identifying film 10 andthe holographic image can be clearly observed through the right-handcircularly polarizing part 30 b as if there is no polarizing plate, theleft-hand circularly polarizing part 30 a becomes dark and neither thereflected light or the holographic image can be observed through theleft-hand circularly polarizing part 30 a. Therefore, it is readilyknown that the reflected light is right-handed circularly polarizedlight and the holographic image is formed of right-handed circularlypolarized light.

If the authenticity identifying film attached to the article is acounterfeit, the reflected light is not circularly polarized light norcan the holographic image formed of circularly polarized light beformed. Accordingly, when the authenticity identifying film 10 isobserved through the circularly polarizing plate 30, the sameselectively reflected light and the same holographic image can be seenthrough the left-hand circularly polarizing part 30 a and the right-handcircularly polarizing part 30 b.

The embodiment 1-2 is able to distinguish authenticity easily by usingthe circularly polarizing plate 30.

Authenticity distinguishment can be more accurately achieved by theelectrooptical measurement of the difference or the ratio in theintensity of transmitted light between the left-hand circularlypolarizing part 30 a and the right-hand circularly polarizing part 30 bthan by the visual observation of the authenticity identifying film 10.The accuracy of authenticity distinguishment can be further improved bythe measurement of the wavelength of the detected reflected light.

Embodiment 1-3

FIG. 6 is a typical sectional view of assistance in explaining a methodof using an authenticity identifying film in an embodiment 1-3 accordingto the present invention.

An authenticity identifying film 10 has a reflective film 11, aprotective layer 12, a light absorbing layer 13, a base film 14 and ahologram forming layer 15.

In this embodiment, both the surfaces of the reflective film 11 aresmooth, which is different from the reflective films employed in theembodiments 1-1 and 1-2.

The hologram forming layer 15 is laminated to the reflective film 11 toreflect light penetrating through the reflective film 11 in a directiondifferent from that of the reflected light from the reflective film 11to form a holographic image. One surface of the hologram forming layer15 is provided with a hologram forming part 15 a. The reflective film 11reflects either of right-handed circularly polarized light orleft-handed circularly polarized light. The hologram forming layer 15transmits circularly polarized light of one hand of polarizationopposite the other hand of polarization of the reflected light reflectedby the reflective film 11, and the hologram forming part 15 a reflectsthe light transmitting through the reflective film 11 to form aholographic image. The hologram forming layer 15 is formed of asynthetic resin that facilitate forming minute irregularities in thehologram forming layer 15. Synthetic resins suitable for forming thehologram forming layer 15 are thermoplastic synthetic resins includingpolyvinyl chlorides, acrylic resins, polycarbonates and polystyrenes,thermosetting synthetic resins including unsaturated polyester resins,melamine resins and epoxy resins, and mixtures each of a thermoplasticsynthetic resin and a thermosetting synthetic resin. The hologramforming layer 15 of such a resin is bonded to the reflective film 11.The hologram forming layer 15 may be formed by applying a solution ofsuch a resin or a molten resin to the surface of the reflective film 11.The hologram forming layer 15 may be formed on a transparent film byapplying a solution or a molten resin to the transparent film, and thetransparent film carrying the hologram forming layer 15 may be attachedto the surface of the reflective film 11.

The authenticity of the authenticity identifying film 10 in thisembodiment also can be easily distinguished.

Since the reflective film 11 and the hologram forming layer 15 areseparate components, the reflective film 11 and the hologram forminglayer 15 can be easily formed by separate processes, respectively.

Since the reflective film 11 and the hologram forming layer 15 can beseparately manufactured, different kinds of authenticity identifyingfilms 10 can be manufactured by combining one kind of all-purposereflective film 11 and hologram forming layers 15 respectively havinghologram forming parts 15 a of different patterns.

Modifications

The present invention is not limited in its practical application to theforegoing embodiments 1-1, 1-2 and 1-3, and many changes andmodifications are possible.

For example, the hologram forming parts 11 a and 15 a may be providedwith a plurality of fine irregular sections, each having groovesextended in different directions, respectively. Such a hologram formingpart reflects reflected light in a plurality of directions and henceauthenticity distinguishing accuracy can be improved by the detection ofthe reflected light reflected in different directions.

Although the twisting direction of the elongated molecules of thecholesteric liquid crystal phase of the reflective films in theembodiments 1-1, 1-2 and 1-3 is right-handed, the same may beleft-handed for the same effects.

The hologram forming layers 11 a and 15 a may be provided with adeposited film to form a sharp holographic image.

Although the hologram forming part 11 a is formed in a surface of thereflective film 11 contiguous with the light absorbing layer 13 in FIG.1, the hologram forming part 11 a may be formed in the surfacecontiguous with the protective layer 12. In such a case, light incidenton the authenticity identifying film 10 is reflected by the hologramforming part 11 a in a predetermined direction to form a holographicimage, and the light penetrating into the reflective film 11 isreflected in a direction different from that of the reflected lightreflected by the hologram forming part 11 a. Thus, the effect of thisauthenticity identifying film is the same as that of the authenticityidentifying film 10 shown in FIG. 1.

If the reflective film 11 is sufficiently hard, the protective layer 12may be omitted.

If an article to which the authenticity identifying film 10 is attachedhas a light absorbing property, the light absorbing layer 13 may beomitted.

If the reflective film 11, the protective layer 12 or the lightabsorbing layer 13 has a sufficient self-supporting ability or theauthenticity identifying film 10 need not have self-supporting ability,the authenticity identifying film 10 need not be necessarily providedwith the base film 14.

As is apparent from the foregoing description, according to the presentinvention, the reflective film provided with the hologram forming partis difficult to forge and facilitates the identification ofauthenticity.

The reflective film and the hologram forming layer attached to thereflective film or sandwiched between the adjacent surfaces can bemanufactured by separate processes, respectively.

Since the reflective film is a liquid crystal film. the same has aselective reflectivity and a circularly polarized light selectivity.

Since the reflective film is formed by fixing a cholesteric phase, thereflective film has a selective reflectivity and a circularly polarizedselectivity.

The hologram forming part having an embossed hologram can be easilyformed.

The light source unit for illuminating the authenticity identifying filmand the detector for detecting the rotating direction of the circularpolarized light facilitates authenticity identification.

The detector that detects only the light of a wavelength in apredetermined waveband simplifies authenticity identification.

The detector that detects the intensity of transmitted light enablesaccurate authenticity identification.

The light source unit and/or the detector having the polarizing plate,the phase plate and or the band-pass filter can be easily manufactured.

When the reflected light produced by reflecting right-handed circularlypolarized light and left-handed circularly polarized light is detected,it is decided that the authenticity identifying film is authentic whenonly either of the reflected light of the right-handed circularlypolarized light or that of the left-handed circularly polarized lightcan be detected, so that authenticity can be easily distinguished.

When the reflected light produced by reflecting light includingright-handed circularly polarized light and left-handed circularlypolarized light is detected, it is decided that the authenticityidentifying film is a counterfeit when only the reflected lightreflected in one direction can be detected and it is decided that theauthenticity identifying film is authentic when the reflected lightreflected in the different direction and the holographic image can bedetected. Therefore, authenticity can be easily distinguished.

When the authenticity identifying film is observed visually through anexamining tool that transmits only either of right-handed circularlypolarized light or left-handed circularly polarized light, it is decidedthat the authenticity identifying film is authentic. Thus, authenticitycan be easily distinguished.

When light intensity difference is measured electrooptically by using ameasuring tool that transmits only either of right-handed circularlypolarized light or left-handed circularly polarized light, it is decidedwhether or not the authenticity identifying film is authentic on thebasis of the light intensity difference. Thus, authenticity can beaccurately distinguished.

Second Embodiment

Embodiment 2-1

An authenticity identifying film in an embodiment 2-1 according to thepresent invention will be described with reference to FIG. 7. Referringto FIG. 7, an authenticity identifying film 40 has a reflective film 41,a hologram forming layer 43 laminated to the reflective film 41, anadhesive layer 45 formed on the hologram forming layer 43, an additionaladhesive layer 42 formed on a surface of the reflective film 41 oppositethe surface on which the hologram forming layer 43 is laminated, and abase film 44.

The authenticity identifying film 40 is attached to an article 20 withthe adhesive layer 45. The hologram forming layer 43 has a hologramforming part 43 a. A hologram forming part may be formed in thereflective film 41 and the hologram forming layer 43 may be omitted.

The authenticity identifying film 40 is of a sealed type or a laminatedtype. The base film 44 remains on the authenticity identifying film 40after the authenticity identifying film 40 has been bonded to thearticle 20.

The authenticity identifying film 40 may be of a hot-stamping type or ofa thermal transfer ribbon type. When the authenticity identifying film40 is of a hot-stamping type or a thermal transfer ribbon type, the basefilm 44 is removed after the authenticity identifying film 40 has beenbonded to the article 20 and hence the authenticity identifying film 40is provided with a separating layer and a protective layer instead ofthe additional adhesive layer 42.

The authenticity identifying film 40 may be provided with additionallayers other than the foregoing layers.

Embodiment 2-2

An embodiment 2-2 according to the present invention will be describedwith reference to FIGS. 8 to 10.

Referring to FIG. 8, the authenticity identifying film 40 shown in FIG.7 is attached to an article 20, such as a plastic card or a bankingcard, by a hot-stamping process, a sticking process or a thermaltransfer process. The surface of the article 20 is coated with, forexample, a black light absorbing layer to enable the effectiveobservation of the reflected light reflected by the reflective film 41and the holographic image formed by the hologram forming layer 43.Characters and a pattern 50 may be formed on the surface of theauthenticity identifying film 40.

If an effort is made to separate the authenticity identifying film 40stuck to the article 20 by a sticking process from the article 20, thereflective film 41 is delaminated because the adhesions between thecomponent layers of the authenticity identifying film 40 and theadhesion between the authenticity identifying film 40 and the article 20are higher than the strength of the reflective film 41. Thus, thereflective film 41 is delaminated if an effort is made to separate theauthenticity identifying film 40 from the article 20 with an intentionto manipulate the authenticity identifying film 40 for dishonestalteration and hence dishonest alteration of the authenticityidentifying film 40 is impossible.

A modification will be described with reference to FIG. 9. Amodification shown in FIG. 9 has the authenticity identifying film 40,the article 20 and a photograph sandwiched between the authenticityidentifying film 40 and the article 20. The modification shown in FIG. 9is the same in other respects as the embodiment shown in FIG. 8. Asshown in FIG. 9, the photograph 51 enables the identification of theowner of the article 20. If the authenticity identifying film 40 isseparated from the article 20 with an intention replacing the photographwith another one, the reflective film 41 is delaminated.

The authenticity identifying film 40 employed in the modification shownin FIG. 9 is not provided with any light absorbing layer (FIG. 7), theauthenticity identifying film 40 is transparent and hence the photograph51 attached to the article can be surely recognized through theauthenticity identifying film 40.

Another modification will be described with reference to FIG. 10. In themodification shown in FIG. 10, characters and patterns 50 are formedover the entire surface of an article 20, and an authenticityidentifying film 40 of the same size as the article 20 is laminated tothe article 20. The modification shown in FIG. 10 is the same in otherrespects as that shown in FIG. 9.

Embodiment 2-3

An embodiment 2-3 according to the present invention will be describedwith reference to FIG. 11. FIG. 11 is a view of assistance in explaininga method of applying an authenticity identifying film 48 to an article20.

As shown in FIG. 11, a transfer sheet 47 having a base film 47 a and atransfer layer 47 b is disposed on the article 20, and a hot stamper ora transfer head 46 is lowered from above the transfer sheet 47 (FIG.11(a)). The hot stamper or the transfer head 46 applies heat andpressure to the transfer sheet 47 to transfer a part of the transferlayer 47 b to the article 20. In this manner, an authenticityidentifying film 48 is formed on the article 20 by the part of thetransfer layer 47 b.

The authenticity identifying film 48 has a separating layer and aprotective layer 42, a reflective film 41, a hologram forming layer 43and an adhesive layer 45 (FIG. 7).

Embodiment 2-4

An embodiment 2-4 according to the present invention will be describedwith reference to FIG. 12. The embodiment shown in FIG. 12 is a cardformed by attaching the circularly polarizing plate 30 shown in FIG. 5to a plastic or paper base 32. The circularly polarizing plate 30 has aleft-hand circularly polarizing part 30 a, a right-hand circularlypolarizing part 30 b, and a support part 31 disposed at the boundarybetween the left-hand circularly polarizing part 30 a and the right-handcircularly polarizing part 30 b.

Each of the left-hand circularly polarizing part 30 a and the right-handcircularly polarizing part 30 b is formed by laminating a polarizingfilm and a phase contrast film. The phase contrast film is on the sideof an authenticity identifying film. The directions of the absorptionaxes of the polarizing films of the left-hand circularly polarizing part30 a and the right-hand circularly polarizing part 30 b areperpendicular to each other. The strength of the circularly polarizingplate 30 is maintained by the support part 31.

The circularly polarizing plate 30 has a visual effect as shown in FIG.5. When the photograph of the embodiments shown in FIGS. 9 and 10 areobserved (FIG. 9), the left-hand circularly polarizing part 30 aconceals the holographic image and only the photograph can be observed,and the right-hand circularly polarizing part 30 b emphasizes theholographic image (FIG. 10).

What is claimed is:
 1. An authenticity identifying film comprising: areflective film comprising a liquid crystal film having a cholestericphase and having a circularly polarized light selectively to reflectonly either of right-handed circularly polarized light or left-handedcircularly polarized light of incident light to produce reflected light,wherein the reflective film is provided with a hologram forming partthat reflects circularly polarized light of the same circularpolarization as that of the reflected light in a direction differentfrom that of the reflected light to form a holographic image, andwherein the reflective film comprises a front surface on the lightincidence side and a rear surface on the side opposite to the lightincidence side, and the front surface of the reflective film is a flatsurface and the hologram forming part is provided on the rear surface ofthe reflective film causing the thickness of the reflective film to varydue to the thickness variation of the hologram forming part.
 2. Theauthenticity identifying film according to claim 1, wherein the hologramforming part includes an embossed hologram.
 3. The authenticityidentifying film according to claim 1 further comprising: an adhesivelayer to be attached to an article.
 4. The authenticity identifying filmaccording to claim 3, wherein the reflective film is destroyed when theauthenticity identifying film is separated from the article.
 5. Theauthenticity identifying film according to claim 3 further comprising: aprotective film covering a surface of the reflective film opposite asurface of the reflective film facing an article.
 6. The authenticityidentifying film according to claim 3 further comprising: a base filmattached by an additional adhesive layer to a surface of the reflectivefilm opposite a surface of the reflective film facing the article. 7.The authenticity identifying film according to claim 3 furthercomprising: a light absorbing layer interposed between the reflectivefilm and the adhesive layer.
 8. An authenticity identifying filmcomprising: a reflective film comprising a liquid crystal film having acholesteric phase and having a circularly polarized light selectively toreflect only either of right-handed circularly polarized light orleft-handed circularly polarized light of incident light to producereflected light; a hologram forming layer laminated to the reflectivefilm, having a hologram forming part that reflects circularly polarizedlight of the opposite circular polarization to that of the reflectedlight in a direction different from that of the reflected light to forma holographic image, and wherein the reflective film comprises a frontsurface on the light incidence side and a rear surface on the sideopposite to the light incidence side, and both the front surface and therear surface of the reflective film are flat surfaces, the holographicforming layer having a front surface and a rear surface being laminatedon the rear surface of the reflective film, the front surface of thehologram forming layer being a flat surface, and the hologram formingpart being provided on the rear surface of the hologram forming layer.9. An article with an authenticity identifying film comprising: anauthenticity identifying film comprising a reflective film comprising aliquid crystal film having a cholesteric phase and having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, the reflective film beingprovided with a hologram forming part that reflects circularly polarizedlight of the same circular polarization as that of the reflected lightin a direction different from that of the reflected light to form aholographic image, the reflective film comprising a front surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, the front surface of the reflective film being aflat surface, and the hologram forming part being provided on the rearsurface of the reflective film causing the thickness of the reflectivefilm to vary due to the thickness variation of the hologram formingpart; an article to which the authenticity identifying film is bonded;and a photograph interposed between the article and the authenticityidentifying film.
 10. An authenticity identifying system comprising: anauthenticity identifying film comprising a reflective film comprising aliquid crystal film having a cholesteric phase and having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, the reflective film beingprovided with a hologram forming part that reflects circularly polarizedlight of the same circular polarization as that of the reflected lightin a direction different from that of the reflected light to form aholographic image, the reflective film comprising a front surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, the front surface of the reflective film being aflat surface, and the hologram forming part being provided on the rearsurface of the reflective film; a light source unit for irradiating theauthenticity identifying film with light; and a detecting unit fordetecting the reflected light from the authenticity identifying film andthe holographic forming part causing the thickness of the reflectivefilm to vary due to the thickness variation of the hologram formingpart.
 11. The authenticity identifying system according to claim 10,wherein the detecting unit is capable of detecting only light in apredetermined waveband.
 12. The authenticity identifying systemaccording to claim 10, wherein the detecting unit is capable ofmeasuring the intensity of transmitted light by the detecting unit. 13.The authenticity identifying system according to claim 10, wherein atleast either the light source unit or the detecting unit is providedwith a polarizing plate.
 14. The authenticity identifying systemaccording to claim 10, wherein at least either the light source unit orthe detecting unit is provided with a phase plate.
 15. The authenticityidentifying system according to claim 10, wherein at least either thelight source unit or the detecting unit is provided with a band-passfilter.
 16. A method of using an authenticity identifying filmcomprising a reflective film comprising a liquid crystal film having acholesteric phase and having a circularly polarized light selectively toreflect only either of right-handed circularly polarized light orleft-handed circularly polarized light of incident light to producereflected light, the reflective film being provided with a hologramforming part that reflects circularly polarized light of the samecircular polarization as that of the reflected light in a directiondifferent from that of the reflected light to from a holographic image,the reflective film comprising a front surface on the light incidenceside and a rear surface on the side opposite to the light incidenceside, the front surface of the reflective film being a flat surface, andthe hologram forming part being provided on the rear surface of thereflective film causing the thickness of the reflective film to vary dueto the thickness variation of the hologram forming part; said methodcomprising the steps of: irradiating the authenticity identifying filmwith right-handed circularly polarized light and left-handed circularlypolarized light respectively; and deciding that the authenticityidentifying film is authentic when either right-handed circularlypolarized light or left-handed circularly polarized light, which isreflected from the reflective film, can be detected and the othercircularly polarized light, which is not reflected from the reflectivefilm, cannot be detected.
 17. A method of using an authenticityidentifying film comprising a reflective film comprising a liquidcrystal film having a cholesteric phase and having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, the reflective film beingprovided with a hologram forming part that reflects circularly polarizedlight of the same circular polarization as that of the reflected lightin a direction different from that of the reflected light to form aholographic image, the reflective film comprising a front surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, the front surface of the reflective film being aflat surface, and the hologram forming part being provided on the rearsurface of the reflective film causing the thickness of the reflectivefilm to vary due to the thickness variation of the hologram formingpart; said method comprising the steps of: irradiating the authenticityidentifying film with light including right-handed circularly polarizedlight and left-handed circularly polarized light; and deciding that theauthenticity identifying film is authentic when the holographic imagefrom the authenticity identifying film can be read in a directiondifferent from that of the reflected light.
 18. A method of using anauthenticity identifying film comprising a reflective film comprising aliquid crystal film having a cholesteric phase and having a circularlypolarized light selectively to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, the reflective film beingprovided with a hologram forming part that reflects circularly polarizedlight of the same circular polarization as that of the reflected lightin a direction different from that of the reflected light to form aholographic image, the reflective film comprising a flat surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, the front surface on the reflective film being aflat surface, and the hologram forming part being provided on the rearsurface of the reflective film causing the thickness of the reflectivefilm to vary due to the thickness variation of the hologram formingpart; said method comprising the steps of: irradiating the authenticityidentifying film with light including right-handed circularly polarizedlight and left-handed circularly polarized light; and deciding that theauthenticity identifying film is authentic when the film has a part thatcannot be visually recognized when the authenticity identifying film isobserved visually through an examining tool having region that transmitsof right-handed circularly polarized light and region transmitsleft-handed circularly polarized light.
 19. A method of using anauthenticity identifying film comprising a liquid crystal film having acholesteric phase and having a circularly polarized light selectivity toreflect only either of right-handed circularly polarized light orleft-handed circularly polarized light of incident light to producereflected light, the reflective film being provided with a hologramforming part that reflects circularly polarized light of the samecircular polarization as that of the reflected light in a directiondifferent from that of the reflected light to form a holographic image,the reflective film comprising a flat surface on the light incidenceside and a rear surface on the side opposite to the light incidenceside, the front surface on the reflective film being a flat surface, andthe hologram forming part being provided on the rear surface of thereflective film causing the thickness of the reflective film to vary dueto the thickness variation of the hologram forming part; said methodcomprising the steps of: irradiating the authenticity identifying filmwith light including right-handed circularly polarized light andleft-handed circularly polarized light; measuring a light intensitydifference between intensities of right-handed circularly polarizedlight and that of left-handed circularly polarized light transmitted byan examining tool having region that transmits of right-handedcircularly polarized light and region transmits left-handed circularlypolarized light; and deciding whether or not the authenticityidentifying film is authentic on the basis of the light intensitydifference.
 20. An article with an authenticity identifying filmcomprising: an authenticity identifying film comprising a reflectivefilm comprising a liquid crystal film having a cholesteric phase andhaving a circularly polarized light selectivity to reflect only eitherof right-handed circularly polarized light or left-handed circularlypolarized light of incident light to produce reflected light, and ahologram forming layer laminated to the reflective film, having ahologram forming part that reflects circularly polarized light of theopposite circular polarization to that of the reflected light in adirection different from that of the reflected light to form aholographic image, the reflective film comprising a front surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, both the front surface and the rear surface of thereflective film being flat surfaces, and the hologram forming layerhaving a front surface and a rear surface being laminated on the rearsurface of the reflective film, the front surface of the hologramforming layer being a flat surface and the hologram forming part beingprovided on the rear surface of the hologram forming layer; an articleto which the authenticity identifying film is bonded; and a photographinterposed between the article and the authenticity identifying film.21. An authenticity identifying system comprising: an authenticityidentifying film comprising a reflective film comprising a liquidcrystal film having a cholesteric phase and having a circularlypolarized light selectively to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, and a hologram forming layerlaminated to the reflective film, having a hologram forming part thatreflects circularly polarized light of the opposite circularpolarization to that of the reflected light in a direction differentfrom that of the reflected light to form a holographic image, thereflective film comprising a front surface on the light incidence sideand a rear surface on the side opposite to the light incidence side,both the front surface and the rear surface of the reflective film beingflat surfaces, and the hologram forming layer having a front surface anda rear surface being laminated on the rear surface of the reflectivefilm, the front surface of the hologram forming layer being a flatsurface, and the hologram forming part being provided on the rearsurface of the hologram forming layer; a light source unit forirradiating the authenticity identifying film with light; and adetecting unit for detecting the reflected light from the authenticityidentifying film and the holographic image causing the thickness of thereflective film to vary due to the thickness variation of the hologramforming part.
 22. A method of using an authenticity identifying filmcomprising a reflective film comprising a liquid crystal film having acholesteric phase and having a circularly polarized light selectivity toreflect only either of right-handed circularly polarized light orleft-handed circularly polarized light of incident light to producereflected light, and a hologram forming layer laminated to thereflective film, having a hologram forming part that reflects circularlypolarized light of circular polarization opposite that of the reflectedlight in a direction different from that of the reflected light to forma holographic image, the reflective film comprising a front surface onthe light incidence side and a rear surface on the side opposite to thelight incidence side, both the front surface and the rear surface of thereflective film being flat surfaces, and the hologram forming layerhaving a front surface and a rear surface being laminated on the rearsurface of the reflective film, the front surface of the hologramforming layer being a flat surface, and the hologram forming part beingprovided on the rear surface of the hologram forming layer; said methodcomprising the steps of: irradiating the authenticity identifying filmwith right-handed circularly polarized light and left-handed circularlypolarized light respectively; and deciding that the authenticityidentifying film is authentic when either right-handed circularlypolarized light or left-handed circularly polarized light, which isreflected from the reflective film, can be detected and the othercircularly polarized light, which is not reflected from the reflectivefilm, cannot be detected.
 23. A method of using an authenticityidentifying film comprising a reflective film comprising a liquidcrystal film having a cholesteric phase and having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, and a hologram forming layerlaminated to the reflective film, having a hologram forming part thatreflects circularly polarized light of circular polarization oppositethat of the reflected light in a direction different from that of thereflected light to form a holographic image, the reflective filmcomprising a front surface on the light incidence side and a rearsurface on the side opposite to the light incidence side, both the frontsurface and the rear surface of the reflective film being flat surfaces,and the hologram forming layer having a front surface and a rear surfacebeing laminated on the rear surface of the reflective film, the frontsurface of the hologram forming layer being a flat surface, and thehologram forming part being provided on the rear surface of the hologramforming layer; said method comprising the steps of: irradiating theauthenticity identifying film with light including right-handedcircularly polarized light and left-handed circularly polarized light;and deciding that the authenticity identifying film is authentic whenthe holographic image from the authenticity identifying film can be readin a direction different from that of the reflected light.
 24. A methodof using an authenticity identifying film comprising a reflective filmcomprising a liquid crystal film having a cholesteric phase and having acircularly polarized light selectivity to reflect only either ofright-handed circularly polarized light or left-handed circularlypolarized light of incident light to produce reflected light, and ahologram forming layer laminated to the reflective film, having ahologram forming part that reflects circularly polarized light ofcircular polarization opposite that of the reflected light in adirection different from that of the reflected light to form aholographic image, the reflective film comprising a flat surface on thelight incidence side and a rear surface on the side opposite to thelight incidence side, both the front surface and the rear surface on thereflective film being flat surfaces, and the hologram forming layerhaving a front surface and a rear surface being laminated on the rearsurface of the reflective film, the front surface of the hologramforming layer being a flat surface, and the hologram forming part beingprovided on the rear surface of the hologram forming layer; said methodcomprising the steps of: irradiating the authenticity identifying filmwith light including right-handed circularly polarized light andleft-handed circularly polarized light; and deciding that theauthenticity identifying film is authentic when the film has a part thatcannot be visually recognized when the authenticity identifying film isobserved visually through an examining tool having region that transmitsof right-handed circularly polarized light and region transmitsleft-handed circularly polarized light.
 25. A method of using anauthenticity identifying film comprising a reflective film comprising aliquid crystal film having a cholesteric phase and having a circularlypolarized light selectivity to reflect only either of right-handedcircularly polarized light or left-handed circularly polarized light ofincident light to produce reflected light, and a hologram forming layerlaminated to the reflective firm, having a hologram forming part thatreflects circularly polarized light of the opposite circularpolarization to that of the reflected light in a direction differentfrom that of the reflected light to form a holographic image, thereflective film comprising a flat surface on the light incidence sideand a rear surface on the side opposite to the light incidence side,both the front surface and the rear surface on the reflective film beingflat surfaces, and the hologram forming layer having a front surface anda rear surface being laminated on the rear surface of the reflectivefilm, the front surface of the hologram forming layer being a flatsurface, and the hologram forming part being provided on the rearsurface of the hologram forming layer; said method comprising the stepsof: irradiating the authenticity identifying film with light includingright-handed circularly polarized light and left-handed circularlypolarized light; measuring a light intensity difference betweenintensities of right-handed circularly polarized light and that ofleft-handed circularly polarized light transmitted by an examining toolhaving region that transmits of right-handed circularly polarized lightand region transmits left-handed circularly polarized light; anddeciding whether or not the authenticity identifying film is authenticon the basis of the light intensity difference.